Introduction

What is tenosynovitis?

Tenosynovitis is an inflammatory condition affecting the tendon’s synovial sheath.¹

Common causes and risk factors

Common causes

1. Repetitive motion and overuse:

Repetitive motions such as typing, assembly line, and sports (e.g., tennis, golf) may lead to irritation and inflammation of the tendon sheath.

2. Autoimmune diseases:

Diseases such as rheumatoid arthritis (RA), lupus, and psoriatic arthritis may result in immune-mediated inflammation of the tendons.

3. Chronic inflammatory conditions:

Gout and diabetes mellitus raise the risk of tendon inflammation through metabolic derangements.

Risk factors

1. Occupational hazards: Repetitive hand or wrist motion jobs, such as carpentry, gardening, or computer mouse use, increase the risk
2. Age: Middle and old age predispose individuals due to lower tendon elasticity and increased wear and tear.
3. Gender: Women, especially postpartum women, are more vulnerable to De Quervain's tenosynovitis⁴
4. Diabetes Mellitus: Hyperglycemia leads to tendon degeneration and inflammation^{2, 3, 5}

Importance of effective management

The most common differential diagnosis of the condition is joint-related diseases and cellulitis. In cellulitis, the condition would mimic tenosynovitis, such that it would be difficult to move the joint because of the swelling and pain. All other conditions affecting the joints, including osteoarthritis, gout, pseudogout, rheumatoid arthritis, and psoriatic arthritis, can also mimic the condition. Recent and old bone injuries and tendon injuries can also resemble stenosing tenosynovitis. Dupuytren contractures may also imitate the stenosing type of tenosynovitis as it hardens the fascia, leading to chronic locking of the fingers.³

Pathophysiology of tenosynovitis

Tenosynovitis is when the tendon sheath, which is a fluid-filled tissue enveloping the tendon, becomes inflamed. The aetiology of tenosynovitis varies, but inflammation and thickening of the tendon sheath are observed in all. This predominantly affects the tendon synovium or the tendon itself and renders it difficult to glide normally. Certain tendons, such as the Achilles tendon, lack a sheath and are not influenced by tenosynovitis. Infectious tenosynovitis may progress and destroy the sheath, tendon, and surrounding structures sequentially.³

Treatment approaches for tenosynovitis

De Quervain tenosynovitis is sometimes self-limiting and can be resolved without treatment. For individuals with ongoing symptoms, splinting, systemic anti-inflammatories, and corticosteroid injections are the most commonly used nonsurgical treatments. Thumb spica splinting might provide some short-term relief for patients, but in the long run, recurrence and failure tend to be high, while compliance tends to be low. Splinting could be an intermediate solution for those who don't want any intervention. Isolated immobilisation of the wrist will only prove helpful in those with mild pain. Additionally, firm immobilisation within a thumb spica cast or rigid splint can be adverse as it may enhance the myxoid degeneration of involved tendons. Hence, immobilisation in a removable semi-rigid splint can be more beneficial. Corticosteroid injection has been noted to yield almost complete relief with a single or double injection in 52% to 90% of patients. Injection is done into the tendon sheath 1 cm proximal to the radial styloid, where the tendons are palpable.

In case of failure to improve or persistence of symptoms after two corticosteroid injections, surgical management can be considered. Surgery is typically carried out on an outpatient basis. It may involve local, regional, or general anaesthesia, and in most instances, a tourniquet to restrict intraoperative haemorrhage and to facilitate the identification of vital anatomic structures. This is achieved through an about 2 cm transverse skin incision over the first dorsal compartment. With care not to damage the branches of the superficial radial sensory nerve, the first dorsal compartment ligament is revealed by blunt dissection. The dorsal edge of the sheath is sharply incised. Subsheaths are recognised and incised when found. With the release of all the subcompartments, the skin is closed, a soft, bulky dressing is placed, and early mobilisation is instituted. Several permutations of surgical interventions have been described in the literature, ranging from endoscopic procedures to subtotal extensor retinaculum excision. In all cases, there are high levels of symptomatic improvement and low complication rates.⁴

Corticosteroid injections

Corticosteroid injection has been found to result in almost complete relief with one or two injections in 52% to 90% of the patients. The injection is done into the tendon sheath 1 cm above the radial styloid, where the tendons are palpable. Efforts should be made to palpably enter both the abductor pollicis longus and extensor pollicis brevis sheaths as deeply as possible within the fibro-osseous tunnel to reduce the risk of hypopigmentation and subcutaneous atrophy. Ultrasound guidance of injection has been shown to enable visualisation and proper injection of the several septae and sheaths that may exist within the first dorsal extensor compartment. The success rate of the corticosteroid injection is higher under ultrasound guidance.⁴

Efficacy of corticosteroid injections in tenosynovitis

About 50% of patients achieve symptomatic relief with a single injection. Another 40% to 45% of patients can be relieved by a second injection. Steroid injection complications that are possible include fat and dermal atrophy and hypopigmentation, which are usually seen with subcutaneous injection and not in the tendon sheath. These can be made better or healed with time. Also, injections given several times within a short period can lead to weakening of tendons, their thinning, and subsequent rupture.⁴

Complications

Infectious/pyogenic tenosynovitis carries a high rate of 38% complications. It leads to finger stiffness that is long-lasting with alterations in the tendon or bone, and additional risk of recurrent hand infection within the deep spaces of the hand, tenolysis, adhesions, and at times requiring amputation. Non-infectious tenosynovitis may further develop into stenosing tenosynovitis, causing long-standing contractures and flexion deformities, treated by surgical intervention. Further, it can also cause secondary carpal tunnel syndrome, or can occasionally occur with ganglion cysts, as demonstrated. Non-infectious tenosynovitis necessitating surgery may also experience secondary issues such as infection, nerve injury, flexor tendon issues, and scarring of the tissue due to the operation.

To avoid infectious tenosynovitis, one should avoid exposure to situations that can infect the hands. Early signs of infection, such as tenderness, pain, contracture, and swelling of a finger, must be observed by the patient and emergent treatment sought. Non-infectious tenosynovitis patients are recommended to avoid activities that worsen symptoms and manage the systemic disease that could be contributing to the disease process.³

Special considerations 

Corticosteroid injections in specific populations (e.g., diabetics, the elderly)

Corticosteroid injections are not entirely harmless and may produce reactions. Stepan et al found that type I diabetics and insulin-dependent diabetics had increased levels of blood glucose for 2 days after an injection. Goldfarb et al found in a double-blind randomised trial that although 33% of patients had flare reactions, the patients responded to additional-articular injections for trigger digits and de Quervain's tenosynovitis with no difference in standard or pH-balanced injections.⁶

Frequency and limitations of repeat injection

For those who receive treatment, the results are great. For those who do not receive treatment, the ensuing pain usually leads to disability. The more permanent result is surgery, but with complications. Cortisone injections do help, but there are recurrences. With cortisone injections, recovery can take 3 to 9 months. All patients must refrain from repetitive movements to avoid the recurrence of symptoms. They will require some of their patients to change their jobs, and some will need to undergo long-term hand rehabilitation exercises.⁴

Conclusion

Nonoperative, also known as conservative management, consists of immobilisation and corticosteroid injections into the first dorsal compartment, which alleviates most patients. For those whose conservative measures fail, our experts will present surgical release of the first dorsal compartment as an effective option. The audience will also be able to explore the critical role of the interprofessional health team in assessing, diagnosing, and managing this condition.⁴